How to restore a Diaphragm First Stage with IP Creep

[macado]

This is helpful. I've got a couple old stubborn Apeks DS4s that I tried to polish the volcano orifice (I have the Apeks polishing tool) and I couldn't get it to lock up. I'm going to inspect the other areas more closely (I tried replacing the entire balance chamber but that didnt help either).

One is an eBay gamble and another one was an old flooded reg. I should probably give up on both of them but I'm going to give them one more try.

 

[rsingler]

The Apeks polishing tool is way too coarse. After you've used it, try to reach the volcano with a pencil tip wrapped in Micromesh. You'll probably have to tape the Micromesh to the shaft of the pencil in order to not waste too much.
MICRO-MESH Sanding/Polishing Kit Variety Pack 3"x4" - 9 Sheets - Made in USA | eBay

 

[macado]

Thanks I just ordered that micromesh so I can play around. This post reminded me I should try to salvage these first stages at least one more time. I'll report back with success or failure. One of them I've tried numerous time with the Apeks polishing tool but I was unsuccessful but I'll give the micromesh a try.

 

[Akimbo]

Have you ever used Diamond Lapping Paste? It is available in very fine grits. Chucking round parts into a drill press set to a low RPM will help keep it square.

 

[flyboy08]

Amazing post! Wish I had your time, patience and brains. But I don’t.....great read.

 

[aoumi]

Used the information in this post when overhauling my MK17 recently. There was a scratch in the balance chamber, which I was able to polish out. After the rebuild, the IP is rock solid. Thanks to @rsingler

 

[macado]

I wanted to report back on an old thread. I had two Apeks DS4s that were sitting on my bench as "unrepairable." I used micromesh 4000 and 6000 to polish the volcano orifice. I took my time and checked it with a cheap USB microscope. You can see attached picture of the before result.

The end result was a success. They instantly lock up after being cycled 30-40 times and hold IP overnight so I would consider that a win.

 

[macado]

Just a useful tip for others. What I have been doing is taking a 8mm hole punch tool and dab of super glue on a pencil eraser to hold the micromesh securely in place. I setup pencils with 4000, 6000, 8000 micromesh and just reglue another 8mm hole punch over when I need a new one

For me it was far more efficient than trying to cut a tiny piece of micromesh.

 

[taimen]

dab of super glue on a pencil eraser to hold the micromesh securely in place

picture?? I am trying to figure out what is the profile of your micromesh tip made this way, or what would be ideal shape to polish Apeks volcano.
Great work, I just got my hands on some micromesh.

 

[macado]

Shiny